1. Field of the Invention
This invention relates to remote sensing and, more particularly, to active remote sensing.
2. Description of Related Art
Active remote sensing may be conceptualized as viewing radiation reflected and/or emitted from a certain location in one or more wavelength regions. Active remote sensing typically utilizes one or more sources of radiation (e.g., infrared, visible, or ultraviolet light) to illuminate a target area while measuring the reflected, scattered and/or emitted radiation at one or more detectors. Such remote sensing may be performed from a moving platform or from a stationary location, each of which may be spatially remote from the target area.
One scheme for performing active remote sensing is to stare at an area with a single detector, while illuminating the area with one or more wavelengths of radiation. Various sources of noise, however, may lower the signal-to-noise ratio (SNR) of the measurement. Examples of such noise typically present in active remote sensing include solar background radiation, 1/f noise (i.e., noise whose power varies inversely with frequency), atmospheric turbulence, and/or scintillation.
Thus, there is a need in the art to perform active remote sensing while maintaining a high SNR.